Fix case of $wgLocalTZoffset from 7e3386d4

The variable is called $wgLocalTZoffset, with lowercase O.
And php variable names are case-sensitive.

This commit is a simple
 sed -i 's/wgLocalTZOffset/wgLocalTZoffset/' includes/Timestamp.php

Change-Id: Iddf9b363c9ddc95938ba8b5e0c134d9ec734109c
Merge "Fix case of $wgLocalTZoffset from 7e3386d4"